Unit 10 Lab
Building a New Structure- Problem Analysis
Errors are common in communication systems due to various reasons like noise, interference, inter-modulation, echoes, signal fading, equipment limitations, etc. Though optical fiber medium is considered to be the best medium, we know that practical media cannot be hundred percent error-free. Here is a list of standard problems in most fiber solutions:
Bit-Error-Ratio is defined as the ratio of the number of bits received in error to the total number of bits transmitted in a specified time interval.
Degraded Minutes (DM) - Degraded Minutes is a group of 60 consecutive seconds after excluding SES, with a BER of 10^-6 or worse. Hence a DM will have at least 5 errors, assuming a data rate of 64 kbit/s.
Available Seconds (AS) The measure of percentage of time for which the circuit is available for use in an error free condition is called Available Seconds.
Unavailable Seconds (US) - If the error activity continues at an excessive level for a significant period of time (say 10 seconds or more) then the circuit is considered to be unavailable. Unavailable Seconds is a measure of percentage of time the circuit is not available for use.
Error Seconds (ES) - A second with at least one anomaly or defect is called Error Second.
List of testers and tools:
Optical Time Domain Reflectometer (OTDR) - OTDR provides various applications such as normal (point-to-point) fiber cable construction testing and fault location, splice